E80.21 Acute intermittent (hepatic) porphyria

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from E80 Disorders of porphyrin and bilirubin metabolism

Includes

• defects of catalase and peroxidase

Risk adjustment (HCC)

• CMS-HCC V28: HCC 50 — Amyloidosis, Porphyria, and Other Specified Metabolic Disorders
• CMS-HCC V22: HCC 23 — Other Significant Endocrine and Metabolic Disorders
• RxHCC V08: HCC 43 — Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders
• ESRD V24: HCC 23

MS-DRG index

Defines the logic of DRG(s) 642 in MDC 10.

Approximate ICD-9-CM (GEMs)

• 277.1 Disorders of porphyrin metabolism (approximate)

Code annotations containing back-references to E80.21

Back-references to E80

• Type 2 Excludes: G11 Hereditary ataxia ("metabolic disorders (E70-E88)")
• Code First: G63 Polyneuropathy in diseases classified elsewhere ("metabolic diseases (E70-E88)")
• Type 2 Excludes: G71 Primary disorders of muscles ("metabolic disorders (E70-E88)")
• Code First: H42 Glaucoma in diseases classified elsewhere ("specified metabolic disorder (E70-E88)")
• Type 2 Excludes: N25.0 Renal osteodystrophy ("metabolic disorders classifiable to E70-E88")
• Type 2 Excludes: N25.81 Secondary hyperparathyroidism of renal origin ("metabolic disorders classifiable to E70-E88")
• Type 1 Excludes: P59 Neonatal jaundice from other and unspecified causes ("jaundice due to inborn errors of metabolism (E70-E88)")

Diagnosis Index entries for E80.21

• Porphyria (South African) › acute intermittent (hepatic) (Swedish)

Nearby codes

• E80 Disorders of porphyrin and bilirubin metabolism
• E80.0 Hereditary erythropoietic porphyria
• E80.1 Porphyria cutanea tarda
• E80.2 Other and unspecified porphyria
• E80.20 Unspecified porphyria
• E80.21 Acute intermittent (hepatic) porphyria (this code)
• E80.29 Other porphyria
• E80.3 Defects of catalase and peroxidase
• E80.4 Gilbert syndrome
• E80.5 Crigler-Najjar syndrome
• E80.6 Other disorders of bilirubin metabolism